Heat exchanger



y 1950 J. NAAB I 2,514,894

HEAT EXCHANGER Filed Dec. 4, 1947 INVENTOR JULIUS NAAB.-

HIS ATTORNEY Patented July 11, 1950 near EXCHANGER Julius Naab, Easton, Pa., assignor to Ingersoll- Rand Company, New York, N. Y., a corporation of New Jersey Application December 4, 1947, Serial No. 789,619

2 Claims. 1

This invention relates to a heat exchanger, and

more particularly to an aitercooler-separator unit adapted to be used in connection with air driven machlnesand tools.

' It is a well established fact that the expansion of compressed air, in air tools, causes a considerable decrease of temperature of the air within the tool which results in condensation of any moisture in the air. Such moisture causes rapid deterioration of the metals in the tool and in some instances, the decrease in temperature is suflicient to cause the formation of ice in and around the exhaust port of the tool thereby lowering its eillciency.

In order to avoid these disadvantages the present practice is to eliminate any moisture present in the compressed air before its delivery to the air tool by passing the compressed air through an aitercooler to condense such moisture and thence through a separator in which the condensate is removed from the compressed air. However, such practice presents a disadvantage whenever floor space is limited in that the aftercooler and separator are in many instances greater in length than the compressor to which they are adapted. Also, in the event that it is necessary to clean the aftercooler, the air tools must be shut down until the cleaning operation is completed or it continued operation of the tools is desired, a complicated and expensive by-pass system for the compressed air must be installed around the aftercooler.

It is, accordingly, one object of my invention to reduce the floor space occupied by a cooler and separator by combining them into one compact unit.

Another object is to enable substantially uninterrupted operation of the air tools by constructing a cooler-separator unit which'will allow operation of the tools after removal of the cooling unit.

A further object is to present a cooler-separator unit in which the cooling unit may be removed with ease.

Other objects will be in part obvious and in part pointed out hereinafter.

In the drawings accompanying this specification and in which similar reference numerals refer to similar parts,

Figure 1 is a vertical elevation, partly in section, of the cooler-separator unit constructed in accordance with the practice oi. the invention,

Figure 2 is a view taken through Figure 1 on the line 2-2, and

Figure 3 is a vertical able cooling unit.

Referring to the drawings, a cooler-separator unit constructed in accordance with the practice of the invention and designated in general by It, comprises a housing I I encircling a heat exchan elevation of the remover l2 having compressed air inlet and outlet openings I3 and i4, respectively. As shown, the heat exchanger includes atubular wall I5 preferably positioned coextensively and concentrically within the housing I] to define a cooling chamber i6 which entirely encases a removable cooling unit I].

The compressed air inlet l3 and an outlet it for the chamber it are, in the present form of the invention, positioned at opposite end portions of the walls i5 thereby requiring the compressed air flowing through the chamber iii to pass along the entire length of the cooling unit ll. The outlet M, positioned in the lower portion of the unit I0, communicates with a chamber it which is formed between the wall i5 and the housing ii to serve, in this instance, as a separator chamber Hi to receive the discharge of compressed air from the heat exchanger [2 for the removal of condensate from such air. The condensate is drained from the separator chamber by a drain pipe til at the lower portion of the housing ii, and the dry compressed air escapes through an outlet 20 at the upper portion of the housing.

The outlet 2G is shown as having a portion which extends into the chamber i8 and is tapered downwardly toward the wall it, or, more specifically the inner end surface 3% of the outlet 20 lies in a plane inclined with respect to the wall it and in a direction away from the inlet end of said wall 85, thereby requiring dry air escaping through the outlet 2fi to come into int mate contact with the upper or warmer portion of the wall i5. This construction presents several advantages in that the dry air is heated somewhat and expands, thereby regaining at least part of the volume decrease occurring during the cooling process, and also the air escaping from the separator chamber necessarily conducts some heat from the wall l5.

Adapted to seat on the ends of the housing ii and secured thereto by bolts 2|, are water boxes 22 which enclose the ends of the cooling chamber i6 and have a portion extending thereinto for conveying cooling water to the unit ll. Encircling the inmost ends of the water boxes 22,

vat their points of connection with the unit it,

are sealin rings 23 to prevent leakage of water from the boxes 22 and toprevent leakage of pressure fluid into the boxes 22 from the cooling chamber It. In this instance, a pair of such rings are supplied for each boxand vents 26 in i the water boxes 22 are positioned between the rings to enable immediate detection of any leakage which may occur around the rings.

External abutments 25 around the water boxes 22 have elevated portions to provide steps 2t of the water boxes 22 and have closed ends with holes therein to receive longitudinally disposed tubes 29 which serve to cool the compressed air flowing through the chamber I9. In furtherance to this end a water supply conduit 35 is connected in the outer end of the box 22 positioned at the air inlet end of the cooler-separator-unit for suD- plying a cooling medium, such as water, to that box.. From said box 22 water is supplied to the coolin unit and passes through the tubes 29 and is discharged therefrom into the box 22 at the opposite end of the unit. The water circuit is completed by a conduit 33 connected to the outer end of last said box 22 which conduit 32 serves, in this instance, as a cooling water discharge passage for the'unit.

In order to extend further the flow path of the compressed air through the chamber l6 and to bring it into repeated intimate contact with the tubes 29, the cooling unit is provided with a series of baflles 30 and 3| which extend transversely of the tubes 29- and are arranged to require the compressed air flowing through the casing to follow a sinuous or serpentine course. That is to say, the baffles 30 and 3| are'arranged in a staggered fashion with the bailles 30 adapted to seat against the left inner surface of the wall 15 and the baffles 3| seat on the opposite surface of the wall. The bafiles are somewhat shorter. in length than the diameter of the casing thereby allowing the compressed air to flow around their free ends. To insure further that compressed air flowing through the chamber I6 is brought into intimate contact withthe tubes 29 and to increase the cooling area presented to such air, the tubes 29 are provided with exterior fins 32, which, for the sake of simplicity, are shown only at the upper end portion of the tubes 29. v

The flow of compressed air through the chamber I6 is further confined to the space adjacent the tubes 29 by plates 33 arranged in parallelism and attached to the sides of the bailles 39 and 3| and having their ends secured to the headers 28. To insure that the plates 33 are suitably positioned with respect to the inlet l3 and the outlet I4 when the cooling unit is assembled in the chamber 16, unequally spaced holes for the bolts 2| require that the water boxes 22 be mounted in such a manner that when the steps 26 and 21 become engaged, the end portions of the plates 33 form an extension for the inlet l3 and outlet I4 and thereby prevent the flow of compressed air external to the cooling unit H.

In practice, if it becomes necessary to clean or repair the tubes of the cooling unit H and at the same time to continue the use of the air line, in which the unit It) is connected, it is merely necessary to remove the water box 22 and the cooling unit I! from the housing II and then, by replacing the water box and closing the --valves (not shown) on the inlet and outlet pipes for the water boxes or by replacing said pipes with pipe plugs, the unit is in conditionto allow the flow of compressed air therethrough.

It will now be readily appreciated, from the above description, that I have presented a cooler- 4 separator unit which is unusually compact and, therefore, occupies only a small area of floor space and hasits partsconveniently arranged to permit ease in disass'embly andass'embly there- .of. WhileI have shown and described the preferred form of my invention, it is to be understood that various changes and modifications may be made therein without departing from the spirit of the invention as set forth in the appended claims.

Iclaim:

1. In a cooler-separator unit, a a tubular wall therein extending from one end to the other of the housing to define a cooling chamber, a pressure fluid inlet and outlet for the chamber, a removable cooling unit within the chamber and having its end spaced from the ends of said chamber, including a pair of parallel plates for confining the flow of pressure fluid through the chamber to a path'within said unit, boxes extending into the ends of said chamber to convey a cooling medium to the cooling unit and to receive such cooling medium discharged from the unit, means on said boxes for positioning said plates to form an extension for said pressure fluid inlet, a separator chamber between the wall and the housing to receive pressure fluid from the cooling chamber, and an outlet for the separator chamber.

2. A cooler-separator unit comprising a housing, a tubular wall extending longitudinally therethrough and having a cooling chamber therein for pressure fluid, a removable cooling unit within said chambe'r water boxes' enclosing the opposite ends of said chamber for supplying cooling fluid to said unit and receiving cooling fluid discharged from said unit, a separator chamber between said wall and the chamber, an inlet in said Wall atone end of the cooling chamber, an': outlet atthe other end of the cooling chamber in communication with the separator chamber, and an outlet extending radially into the separator chamber in the same transverse plane as said inlet, the inner end surface of the last said outlet being in a plane inclined with respect to said tubular wall and away from the inlet end thereof.

' JULIUS NAAB.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name' Date 898,363 Holdsworth Sept. 8, 1908 1,338,479 Zimmermannr Apr'. 27, 1920 1,524,595 Sward Jan. 27, 1925 1,794,336 Jacocks Feb. 24, 1931 1,960,770 Brown May 29, 1934 2,015,490 McAllister Sept. 24, 1935 FOBEIG N PAT ENTS Number Country Date 328,718 Great Britain May 8, 1930 136,236 Germany Dec.-4, 1902 766 Denmark Oct. 1, 1896 housing having- 

